Circulating myeloperoxidase is elevated in septic shock and is associated with systemic organ failure and mortality in critically ill patients.

Background: Neutrophils are elevated in critically ill patients during the systemic inflammatory response to trauma and sepsis. The neutrophil-derived enzyme myeloperoxidase generates reactive oxygen species which can react with host tissue resulting in cell damage and dysfunction. Thus, elevated myeloperoxidase in the circulation may be associated with adverse patient outcomes.

Oxidative cross-linking of calprotectin occurs in vivo, altering its structure and susceptibility to proteolysis.

Calprotectin, the major neutrophil protein, is a critical alarmin that modulates inflammation and plays a role in host immunity by strongly binding trace metals essential for bacterial growth. It has two cysteine residues favourably positioned to act as a redox switch. Whether their oxidation occurs in vivo and affects the function of calprotectin has received little attention.

Oxidative stress in early cystic fibrosis lung disease is exacerbated by airway glutathione deficiency.

Neutrophil-derived myeloperoxidase (MPO) is recognized as a major source of oxidative stress at the airway surface of a cystic fibrosis (CF) lung where, despite limited evidence, the antioxidant glutathione is widely considered to be low. The aims of this study were to establish whether oxidative stress or glutathione status are associated with bronchiectasis and whether glutathione deficiency is inherently linked to CF or a consequence of oxidative stress. MPO was measured by ELISA in 577 bronchoalveolar lavage samples from 205 clinically-phenotyped infants and children with CF and 58 children without CF (ages 0.

Disease activity assessment in IBD: clinical indices and biomarkers fail to predict endoscopic remission.

Background: In the current management paradigm, mucosal healing is preferred over clinical remission as a therapeutic end point in inflammatory bowel disease (IBD) because of the benefits engendered with respect to durability of remission. Colonoscopy, however, is not suitable for regular disease monitoring, and routine clinical assessment is often inaccurate with respect to endoscopic disease activity. The current investigation set out to characterize the relationship that exists between endoscopically determined IBD activity and clinical and biochemical measures of disease severity and to determine clinically useful thresholds for use in clinical practice.

Total soluble and endogenous secretory receptor for advanced glycation endproducts (RAGE) in IBD.

Background And Aims: Recruitment and activation of neutrophils, with release of specific proteins such as S100 proteins, is a feature of inflammatory bowel disease (IBD). Soluble forms of the receptor for advanced glycation endproducts (sRAGE), and variants such as endogenous secretory (esRAGE), can act as decoy receptors by binding ligands, including S100A12. The aims of this study were to determine total sRAGE and esRAGE concentrations in patients with IBD and correlate these with C-reactive protein (CRP), endoscopic scores and clinical disease activity scores.